Hooks are used for many applications, such as for hoisting loads. A hook comes with either a fixed or a swivel eye or with other means for attachment to, for example, a cable or a chain. The hook is forged from a metal selected to meet application requirements, such as strength, corrosion resistance, etc. The hook is formed with a throat which is open to engage a load.
For some applications, it is desirable to provide a latch for closing the hook throat to retain the load in the hook. One common type of latch is attached to a cam or flange formed on the hook adjacent the throat opening. The flange is provided with a hole for attachment of the latch. A spring and holes in the latch are aligned with the flange hole and a bolt is secured through the aligned holes and spring. The spring urges the latch to a position closing the hook throat, while permitting the latch to be pivoted to an open position where the throat is clear for engaging or disengaging a load.
Because of the environment in which hooks are used, the latch may break or become damaged. Therefore, it is common for the hook manufacturers to provide replacement latches for hooks. However, each hook manufacturer makes hooks of its own design. There are no dimension standards for hooks purchased from different manufacturers. This is particularly true for the thickness of the flange on which a latch is mounted. Consequently, a hook latch made for one manufacturer's hooks will not necessarily fit a hook from another manufacturer.